1. Field of the Invention
The present invention relates to a reflection mirror apparatus incorporated in such equipment as a light projector, sterilizing lamp, and developing device, and more particularly to a reflection mirror apparatus which is inexpensive and has improved illumination precision and light focusing performance.
2. Description of the Prior Art
Conventional reflection mirror apparatuses of this kind are made by using a strong cutting drill to cut a metal into a desired shape and subjecting the cut metal to buffing. There is an expensive manufacturing method, which applies resin to the polished aluminum or aluminum alloy, evaporates a high-purity aluminum over the surface of the resin, and then coats a protective glassy film over the aluminum-deposited surface. There are also inexpensive reflection mirrors, among them a mirror made by pressing a rolled metal sheet and one made of synthetic resin. However, no reflection mirror apparatuses are available which have a capability of focusing light on an object effectively and can be manufactured with low cost.
There are various kinds of machining in making the reflection mirror apparatus. In reflection mirror apparatuses, which are manufactured by cutting and polishing a metal, the larger the size of the apparatus, the higher the material cost becomes and the coarser the cut edges and polished surfaces will be. Such cutting and polishing work makes the surface treatment of the reflection mirror uneven, significantly deteriorating the illumination precision.
In the reflection mirror apparatuses, which are made by pressing a rolled metal, although they are less expensive than those made by cutting a metal, they are likely to produce strain in the curved portion of the mirror. This strain tends to increase as the size of the reflection mirror increases, which in turn makes the surface uneven when subjected to plating and other surface treatment, significantly degrading the light reflection performance.